Regrind and Recycling

When reinforced plastics are granulated, the length of their fibers is reduced. When they are reprocessed, with virgin materials or alone, their processability and performance definitely change. So it is important to determine if the change will affect final part performance if it will, a limit for the amount of regrind mix should be determined. 

Impact strength (ASTM D256-73) Per cent elongation (ASTM D1238) 

Number of times molded (Heat history effects performances) 

---

How can compatibilizing additives allow the more efficient use of regrind and recycled PO content ... 

Scrap and Recycle. Acetal resins can be processed with very Htde waste. Spmes, mimers, and out-of-tolerance parts can, in general, be ground and the resins reused. Up to about 25% of regrind can usually be safely recycled into virgin resin. However, the amount of regrind that can be used in a particular circumstance varies. The appropriate Hterature from the suppHer should be consulted. 

Also called regrind and reclaiming. Most processing plants have been reclaiming/ recycling reprocessable TP materials such as molding flash, rejected products, blown... 

The resin supply system should be designed to take advantage of the raw materials in the lowest cost and most effective form. Additives tend to be more expensive than the base resin. Gravimetric rather than volumetric supply of the material is more conducive to minimizing the use of the more expensive feedstock components. The ability of the equipment to utilize reliably 100% of in-plant regrind, additive concentrates, and recycled materials is one of the most important factors to be considered. 

Quite generally, the goal in any blending of polymers is to obtain one or all of the following benefits higher heat distortion temperature (HDT), improved variable temperature impact resistance, solvent resistance, dimensional tolerance, higher flow, utilization of recycle/regrind, and lower cost. 

Wisconsin, Oregon, and California have laws related to recyclability and recycled content of rigid plastic containers. In Wisconsin, plastic containers except those for food, beverages, drugs, and cosmetics, are required to contain 10 percent recycled content. The exemptions do not apply if the U.S. FDA has approved the use of recycled content. However, the law allows remanufactured material (regrind and so forth) to be counted as recycled, and it has had little effect. 

Improved melt processability and recyclability (regrind reusability)... 

S.B. Recyclers buys/sells olf-specillcaiion or off-grade resins, regrind and obsolete or surplus virgin resins. They perform custom grinding. 

Wisconsin Plastic Drain Tile buys/sells regrind and sometimes obsolete or surplus virgin resins. They operate a cleaning or processing system that hanoles post consumer scrap and make recycled plastic corrugated plastic tubing. They nave been in operation for 15 years. 

---